JP2007043792A - Motor starting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the energy efficiency in a motor starting device. <P>SOLUTION: The motor starting device having a main winding and an auxiliary winding is provided with a first positive temperature coefficient thermistor 104, a semiconductor switch 105 connected to the first positive temperature coefficient thermistor 104 in series, and a second negative temperature coefficient thermistor 106 connected to the first positive temperature coefficient thermistor 104 and the semiconductor switch 105 in parallel and controlling turnon and turnoff of the semiconductor switch 105. A thermal loss in the second negative temperature coefficient thermistor 106 is reduced, and a power consumption in the starting device is reduced by covering at least a portion of an outer circumference of the second negative temperature coefficient thermistor 106 with a thermal insulation layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor starting device composed of a single-phase induction motor equipped with a positive temperature coefficient thermistor.

  Conventionally, devices using a positive temperature coefficient thermistor have been widely used as motor starting devices.

  However, in recent years, it has been desired that the energy efficiency is high considering the global environment, and attention is paid to the fact that the power supply voltage continues to be applied to the positive temperature coefficient thermistor even after the motor is started. Some have cut off the power supply voltage applied to a positive temperature coefficient thermistor after starting (for example, refer to patent documents 1).

  Hereinafter, the conventional motor starting device will be described with reference to the drawings.

  FIG. 13 is a circuit diagram using the conventional motor starter described in Patent Document 1, FIG. 14 is a view showing the main part of the conventional motor starter after assembly, and FIG. 15 is an AA of FIG. It is line sectional drawing.

  In FIG. 13, the motor 2 constituting the single-phase induction motor includes a main winding 10 and an auxiliary winding 3 and is connected to an AC power source 7.

  The starting device 1 includes a first positive temperature coefficient thermistor 4 connected in series to the auxiliary winding 3 of the motor 2, a semiconductor switch 5 connected in series to the first positive temperature coefficient thermistor 4, and a first positive temperature coefficient thermistor 4. The second positive characteristic thermistor 6 connected to the auxiliary winding 3 of the motor 2 via the electrode plate A13 in parallel with the semiconductor switch 5 is constituted.

  The first positive temperature coefficient thermistor 4 and the second positive temperature coefficient thermistor 6 are made of, for example, an oxide semiconductor ceramic mainly composed of barium titanate, and have a Curie temperature. It has a characteristic that the value increases rapidly, and self-heat is generated when a current flows, and the electric resistance value increases rapidly.

  The semiconductor switch 5 has a first terminal Ta, a second terminal Tb, and a gate terminal G. The gate terminal G is connected to the second positive temperature coefficient thermistor 6 through an electrode plate B14.

  The semiconductor switch 5 is turned on between the first terminal Ta and the second terminal Tb when a constant current flows through the gate terminal G, and the first terminal Ta and the second terminal when no current flows through the gate terminal G. When Tb is OFF, when no current flows through the second positive temperature coefficient thermistor 6, the resistance value of the second positive temperature coefficient thermistor 6 is small, so a constant current flows through the gate terminal G, and the first terminal Ta, The two terminals Tb are turned on.

  In addition, when a current flows through the second positive characteristic thermistor 6, the resistance value of the second positive characteristic thermistor 6 increases and the current at the gate terminal G decreases, so that there is a gap between the first terminal Ta and the second terminal Tb. It becomes OFF.

  14 and 15, the second positive temperature coefficient thermistor 6 is held with the upper and lower surfaces in contact with the case A11 and the case B12 formed of resin. Also, one of the opposing electrode surfaces is connected to the auxiliary winding 3 via the electrode plate A13, and the other electrode surface is connected to the gate G of the semiconductor switch 5 via the electrode plate B14. Yes.

  The operation and action of the motor starting device configured as described above will be described below.

  When electricity is supplied from the AC power supply 7, a starting current flows through the main winding 10. At the time of start-up, since the temperature of the second positive temperature coefficient thermistor 6 is low and the resistance value is small, a current flows through the gate terminal G, so that the semiconductor switch 5 is turned on.

  Further, since the temperature of the first positive characteristic thermistor 4 is also low and the resistance value is small, a starting current flows through the auxiliary winding 3 and the motor 2 starts operation.

  After the motor 2 is started, the first positive temperature coefficient thermistor 4 self-heats above the Curie temperature within a few seconds, so that the electric resistance value increases rapidly and the current of the auxiliary winding 3 decreases. Disconnected.

  Normally, the first positive temperature coefficient thermistor 4 continues to maintain the self-heating necessary to maintain a high electric resistance value, and thus continues to consume several watts of power during the operation of the motor 2.

  Furthermore, since the power supply voltage is also applied to the second positive temperature coefficient thermistor 6, it self-heats, the resistance value increases and the resistance value increases, so the current to the gate terminal G decreases and the semiconductor switch 5 is turned OFF. .

When the semiconductor switch 5 is turned off, the application of the power supply voltage to the first positive temperature coefficient thermistor 4 is cut off, so that the power consumption of the first positive temperature coefficient thermistor 4 does not occur and power saving can be achieved.
JP-A-6-339291

  However, in the conventional configuration, the heat of the second positive temperature coefficient thermistor 6 is dissipated by heat conduction to the space, the case A11, the case B12, etc., and the heat dissipation to the surroundings is large and the temperature rise cannot be obtained sufficiently. As a result, there has been a problem that an increase in resistance value is reduced and power consumption is increased.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a motor starter with high energy efficiency.

  In order to solve the above-described conventional problems, a motor starting device according to the present invention includes a first positive temperature coefficient thermistor connected in series to an auxiliary winding, and a semiconductor switch connected in series to the first positive temperature coefficient thermistor. And a second positive temperature coefficient thermistor connected in parallel with the positive first sex thermostat and turning the semiconductor switch ON / OFF, and at least a part of the outer peripheral surface of the second positive temperature coefficient thermistor is a heat insulating layer With the enclosure, the heat dissipation effect of the heat insulating layer can suppress the heat radiation to the case contacting with the second positive temperature coefficient thermistor and the atmosphere in the case, and the power consumption of the second positive temperature coefficient thermistor can be saved. It has the action.

  The motor starter of the present invention can provide a motor starter with high energy efficiency.

  The invention according to claim 1 is a motor starting device having a main winding and an auxiliary winding, wherein the first positive thermistor connected in series to the auxiliary winding, the first positive thermistor, A semiconductor switch connected in series; and a first positive-characteristics thermistor and a second positive-characteristics thermistor connected in parallel to the semiconductor switch and controlling on and off of the semiconductor switch. Since at least a part of the outer peripheral surface of the characteristic thermistor is surrounded by a heat insulating layer, the heat conduction to the case and the atmosphere in the case is reduced, and the loss of the second positive characteristic thermistor is reduced. It is possible to provide a motor starter that can reduce the power consumption of the starter and has high power consumption and energy efficiency.

  The invention according to claim 2 is the invention according to claim 1, wherein the heat insulating layer is formed of a vacuum heat insulating material made of a core material and a non-breathable jacket material covering the core material, Since the loss of the second positive temperature coefficient thermistor is reduced by the heat insulating effect of the heat insulating material, the power consumption can be further reduced as compared with the first aspect, and the power consumption of the starting device can be reduced.

  The invention according to claim 3 is the invention according to claim 1, wherein the heat insulating layer is formed of a paint-type heat insulating material applied to the outer peripheral surface of the second positive temperature coefficient thermistor. A heat insulation effect can be obtained with a simple process of simply applying a paint-type heat insulating material to the surface of the characteristic thermistor, and the loss of the second positive temperature coefficient thermistor can be reduced. Power consumption can be reduced.

  The invention according to claim 4 is the invention according to claim 1, wherein the heat insulating layer is formed of a foamed resin, and the second positive temperature coefficient thermistor is formed by the heat insulating effect of the bubbles formed in the foamed resin. Since the heat-insulating layer is a resin molded product, it is easy to process and assemble, and can be manufactured at low cost.

  The invention according to claim 5 is the invention according to claim 1, wherein the heat insulating layer is formed of an air layer defined by the closed space, and the air layer of the closed space is formed on the surface of the case. Since the loss of the second positive temperature coefficient thermistor is reduced by the heat insulating effect of the air layer, no special heat insulating material is required, the assembly is easy and inexpensive, and the power consumption of the starter is reduced. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a circuit diagram of a motor starting device according to Embodiment 1 of the present invention, FIG. 2 is a diagram showing a main part of the motor starting device according to Embodiment 1 of the present invention before assembly, and FIG. It is the BB sectional view after the assembly of FIG.

  Hereinafter, the present embodiment will be described with reference to FIGS. 1, 2, and 3.

  In FIG. 1, a motor 102 constituting a single-phase induction motor includes a main winding 110 and an auxiliary winding 103, and is connected to an AC power source 107. The starting device 101 includes a first positive temperature coefficient thermistor 104 connected in series to the auxiliary winding 103 of the motor 102, a semiconductor switch 105 connected in series to the first positive temperature coefficient thermistor 104, and a first positive temperature coefficient thermistor. A circuit is constituted by a second positive temperature coefficient thermistor 106 connected to the auxiliary winding 103 of the motor 102 via the electrode plate A113 in parallel with the semiconductor switch 104 and the semiconductor switch 105.

  The first positive temperature coefficient thermistor 104 and the second positive temperature coefficient thermistor 106 self-heat when a current flows, and the electric resistance value rapidly increases.

  The semiconductor switch 105 has a first terminal T1, a second terminal T2, and a gate terminal G1, and the gate terminal G1 is connected to the second positive temperature coefficient thermistor 106 through an electrode plate B114.

  When a constant current flows through the gate terminal G1, the first terminal T1 and the second terminal T2 are turned on. When no current flows through the gate terminal G1, the first terminal T1 and the second terminal T2 are turned off. However, when no current flows through the second positive temperature coefficient thermistor 106, the resistance value of the second positive temperature coefficient thermistor 106 is small, so that a constant current flows through the gate terminal G1, and between the first terminal T1 and the second terminal T2. Is turned on.

  Also, when a current flows through the second positive temperature coefficient thermistor 106, the resistance value of the second positive temperature coefficient thermistor 106 increases and the current at the gate terminal G1 decreases, so that there is a gap between the first terminal T1 and the second terminal T2. It becomes OFF.

  2 and 3, one of the opposing electrode surfaces of the second positive temperature coefficient thermistor 106 is connected to the auxiliary winding 103 via the electrode plate A113, and the other electrode surface is connected to the electrode plate B114. To the gate terminal G1 of the semiconductor switch 105.

  The second positive temperature coefficient thermistor 106 is surrounded by a case A111 and a case B112 surrounded by a vacuum heat insulating material 115 which is a heat insulating layer made of a core material and a non-breathable outer covering material covering the core material except for the electrode surface. It has been incorporated. The non-breathable outer jacket material is composed of a plastic film and a laminated film of metal foil.

  The operation and action of the motor starting device configured as described above will be described below.

  When electricity is supplied from the AC power source 107, a starting current flows through the main winding 110. At the time of start-up, since the temperature of the second positive temperature coefficient thermistor 106 is low and the resistance value is small, a current flows through the gate terminal G1, so that the semiconductor switch 105 is turned on.

  Further, since the temperature of the first positive characteristic thermistor 104 is low and the resistance value is small, a starting current flows through the auxiliary winding 103, and the motor 102 starts operation.

  After the motor 102 is started, the first positive temperature coefficient thermistor 104 self-heats above the Curie temperature within a few seconds, so that the electric resistance value increases rapidly, the current of the auxiliary winding 103 decreases, and the auxiliary winding 103 is substantially reduced. Is cut off.

  Furthermore, since the power supply voltage is also applied to the second positive temperature coefficient thermistor 106, it self-heats and the resistance value increases, so that the current to the gate terminal G1 decreases and the semiconductor switch 105 is turned OFF.

  When the semiconductor switch 105 is turned off, the application of the power supply voltage to the first positive temperature coefficient thermistor 104 is cut off, so that the power consumption of the first positive temperature coefficient thermistor 104 does not occur and power saving can be achieved.

  In addition, since the second positive temperature coefficient thermistor 106 is surrounded by the vacuum heat insulating material 115 having excellent heat insulation properties, the heat of the second positive temperature coefficient thermistor 106 is removed except for heat radiation from the opposing electrode surfaces. However, since the heat is hardly transmitted to the case A111 and the case A112, the heat radiation of the second positive temperature coefficient thermistor 106 is extremely reduced.

  In addition, the resistance value of the second positive temperature coefficient thermistor 106 increases as the temperature of self-heating increases. However, if the heat dissipation to the surroundings is large, the temperature cannot be sufficiently increased. Although the power increases and the current of the gate terminal G1 does not sufficiently decrease and the semiconductor switch 105 may not be turned off, this operation error can be avoided in this embodiment.

  Therefore, the power consumption for the heat radiation to the case A111, the case B112, etc. other than the self-heating power of the second positive temperature coefficient thermistor 106 necessary for turning off the semiconductor switch 105 can be suppressed to a very low level. An extremely energy efficient motor starting device can be obtained.

(Embodiment 2)
FIG. 4 is a circuit diagram of the motor starting device according to the second embodiment of the present invention, FIG. 5 is a diagram illustrating a main part of the motor starting device according to the second embodiment of the present invention before assembly, and FIG. It is CC sectional view taken on the line after the assembly of FIG.

  Hereinafter, the present embodiment will be described with reference to FIGS. 4, 5, and 6.

  In FIG. 4, a motor 202 constituting a single-phase induction motor includes a main winding 210 and an auxiliary winding 203 and is connected to an AC power source 207.

  The starting device 201 includes a first positive temperature coefficient thermistor 204 connected in series to the auxiliary winding 203 of the motor 202, a semiconductor switch 205 connected in series to the first positive temperature coefficient thermistor 204, and a first positive temperature coefficient thermistor. A circuit is constituted by a second positive temperature coefficient thermistor 206 connected to the auxiliary winding 203 of the motor 202 via the electrode plate A 213 in parallel with 204 and the semiconductor switch 205.

  The first positive temperature coefficient thermistor 204 and the second positive temperature coefficient thermistor 206 self-heat when a current flows, and the electric resistance value rapidly increases.

  The semiconductor switch 205 has a first terminal T3, a second terminal T4, and a gate terminal G2, and the gate terminal G2 is connected to the second positive temperature coefficient thermistor 206 through the electrode plate B214.

  When a constant current flows through the gate terminal G2, the first terminal T3 and the second terminal T4 are turned on. When no current flows through the gate terminal G2, the first terminal T3 and the second terminal T4 are turned off. However, when no current flows through the second positive temperature coefficient thermistor 206, the resistance value of the second positive temperature coefficient thermistor 206 is small, so that a constant current flows through the gate terminal G2, and between the first terminal T3 and the second terminal T4. Is turned on.

  Also, when a current flows through the second positive temperature coefficient thermistor 206, the resistance value of the second positive temperature coefficient thermistor 206 increases and the current at the gate terminal G2 decreases, so that there is a gap between the first terminal T3 and the second terminal T4. It becomes OFF.

  5 and 6, one of the opposing electrode surfaces of the second positive temperature coefficient thermistor 206 is connected to the auxiliary winding 203 via the electrode plate A 213, and the other electrode surface is connected to the electrode plate B 214. To the gate terminal G2 of the semiconductor switch 205.

  The outer peripheral surface of the second positive characteristic thermistor 206 other than the electrode surface is coated with a paint-type heat insulating material 215 and is held by the case A 211, the case B 212, the electrode plate A 213, and the electrode plate B 214.

  The operation and action of the motor starting device configured as described above will be described below.

  When electricity is supplied from the AC power supply 207, a starting current flows through the main winding 210. At the time of start-up, since the temperature of the second positive temperature coefficient thermistor 206 is low and the resistance value is small, a current flows through the gate terminal G2, so that the semiconductor switch 205 is turned on.

  Further, since the temperature of the first positive characteristic thermistor 204 is low and the resistance value is small, a starting current flows through the auxiliary winding 203 and the motor 202 starts operation.

  After the motor 202 is started, the first positive temperature coefficient thermistor 204 self-heats above the Curie temperature within a few seconds, so that the electric resistance value increases rapidly, the current of the auxiliary winding 203 decreases, and the auxiliary winding 203 is substantially reduced. Is cut off.

  Furthermore, since the power supply voltage is also applied to the second positive characteristic thermistor 206, self-heating occurs and the resistance value increases, so that the current to the gate terminal G2 decreases, and the semiconductor switch 205 is turned OFF.

  When the semiconductor switch 205 is turned off, the application of the power supply voltage to the first positive temperature coefficient thermistor 204 is cut off, so that the power consumption of the first positive temperature coefficient thermistor 204 does not occur and power saving can be achieved.

  In addition, since the second positive temperature coefficient thermistor 206 uses a paint-type heat insulating material 215 that is excellent in heat insulation and needs only to be applied to the outer peripheral surface other than the electrode surface, heat dissipation from the opposite electrode surfaces is excluded. Thus, the heat of the second positive temperature coefficient thermistor 206 is not easily transmitted to the case A 211 and the case B 212, and the heat dissipation of the second positive temperature coefficient thermistor 206 is reduced.

  In addition, the resistance value of the second positive temperature coefficient thermistor 206 increases as the temperature of self-heating increases, but if the heat dissipation to the surroundings is large, the temperature cannot be sufficiently increased, resulting in a small increase in resistance value, resulting in consumption The power increases, and further, the current of the gate terminal G2 does not sufficiently decrease and the semiconductor switch 205 may not be turned off. However, in this embodiment, such an operation error can be avoided.

  Therefore, the power consumption for the heat radiation to the case A 211, the case B 212, etc. other than the self-heating power of the second positive temperature coefficient thermistor 206 necessary for turning off the semiconductor switch 205 can be suppressed to an extremely low level. As a result, an extremely energy efficient motor starting device can be obtained.

  Furthermore, the second positive temperature coefficient thermistor 206 is a simple one in which the paint-type heat insulating material 215 is applied in advance to the outer peripheral surface other than the electrode surface, and no additional parts are required and the number of assembly steps does not increase. A starter with high productivity and low cost can be obtained.

(Embodiment 3)
FIG. 7 is a circuit diagram of a motor starting device according to the third embodiment of the present invention, FIG. 8 is a diagram showing a main part of the motor starting device according to the third embodiment of the present invention before assembly, and FIG. It is the DD sectional view taken on the line after the assembly of FIG.

  Hereinafter, the present embodiment will be described with reference to FIG. 7, FIG. 8, and FIG.

  In FIG. 7, a motor 302 constituting a single-phase induction motor includes a main winding 310 and an auxiliary winding 303 and is connected to an AC power supply 307. The starter 301 includes a first positive temperature coefficient thermistor 304 connected in series to the auxiliary winding 303 of the motor 302, a semiconductor switch 305 connected in series to the first positive temperature coefficient thermistor 304, and a first positive temperature coefficient thermistor. The second positive temperature coefficient thermistor 306 is connected to the auxiliary winding 303 of the motor 302 via the electrode plate A313 in parallel with 304 and the semiconductor switch 305.

  The first positive temperature coefficient thermistor 304 and the second positive temperature coefficient thermistor 306 self-heat when a current flows, and the electric resistance value rapidly increases.

  The semiconductor switch 305 has a first terminal T5, a second terminal T6, and a gate terminal G3, and the gate terminal G3 is connected to the second positive temperature coefficient thermistor 306 via the electrode plate B314.

  When a constant current flows through the gate terminal G3, the first terminal T5 and the second terminal T6 are turned on. When no current flows through the gate terminal G3, the first terminal T5 and the second terminal T6 are turned off. However, when no current flows through the second positive temperature coefficient thermistor 306, the resistance value of the second positive temperature coefficient thermistor 306 is small, so that a constant current flows through the gate terminal G3, and between the first terminal T5 and the second terminal T6. Is turned on.

  Further, when a current flows through the second positive characteristic thermistor 306, the resistance value of the second positive characteristic thermistor 306 increases and the current of the gate terminal G3 decreases, so that the first terminal T5 and the second terminal T6 are connected. It becomes OFF.

  8 and 9, one of the opposing electrode surfaces of the second positive temperature coefficient thermistor 306 is connected to the auxiliary winding 303 via the electrode plate A313, and the other electrode surface is connected to the electrode plate B314. To the gate terminal G3 of the semiconductor switch 305.

  The second positive temperature coefficient thermistor 306 is held by a case A311, a case B312, an electrode plate A313, and an electrode plate B314 formed of foamed resin.

  The operation and action of the motor starting device configured as described above will be described below.

  When electricity is supplied from the AC power supply 307, a starting current flows through the main winding 310. At the time of start-up, since the temperature of the second positive temperature coefficient thermistor 306 is low and the resistance value is small, a current flows through the gate terminal G3, so that the semiconductor switch 305 is turned on.

  Further, since the temperature of the first positive characteristic thermistor 304 is also low and the resistance value is small, a starting current flows through the auxiliary winding 303 and the motor 302 starts operation.

  After the motor 302 is started, the first positive temperature coefficient thermistor 304 self-heats above the Curie temperature in a few seconds, so that the electric resistance value increases rapidly, the current of the auxiliary winding 303 decreases, and the auxiliary winding 303 is substantially reduced. Is cut off.

  Further, since the power supply voltage is also applied to the second positive characteristic thermistor 306, self-heating occurs and the resistance value increases, so that the current to the gate terminal G3 decreases, and the semiconductor switch 305 is turned off.

  When the semiconductor switch 305 is turned off, the application of the power supply voltage to the first positive temperature coefficient thermistor 304 is cut off, so that the power consumption of the first positive temperature coefficient thermistor 304 does not occur and power saving can be achieved.

  In addition, the case A311 and the case B312 that are in contact with the second positive temperature coefficient thermistor 306 are formed of a foamed resin having excellent heat insulating properties. The heat of the positive temperature coefficient thermistor 206 is not easily transmitted to the case A 311 and the case B 312, and the heat radiation of the second pressure characteristic thermistor 206 is reduced.

  The resistance value of the second positive temperature coefficient thermistor 306 increases as the self-heating temperature rises. However, if the heat dissipation to the surroundings is large, the temperature rise cannot be sufficiently obtained. In addition, the semiconductor switch 305 may not be turned OFF because the current of the gate terminal G3 is not sufficiently lowered and the semiconductor switch 305 may not be turned off. In this embodiment, such an operation error can be avoided.

  Therefore, the power consumption for the heat radiation to the case A 311 and the case B 312 other than the self-heating power of the second positive temperature coefficient thermistor 306 necessary for turning off the semiconductor switch 305 can be suppressed to a very low level. As a result, an extremely energy efficient motor starting device can be obtained.

  Furthermore, since the molding of the case A311 and the case B312 is merely foamed resin molding, no additional parts are required and the number of assembly steps is not increased, so that a highly efficient and inexpensive starting device can be obtained.

(Embodiment 4)
FIG. 10 is a circuit diagram of the motor starting device according to the fourth embodiment of the present invention, FIG. 11 is a diagram showing the main parts of the motor starting device according to the fourth embodiment of the present invention before assembly, and FIG. It is the EE sectional view taken on the line after the assembly of FIG.

Hereinafter, the present embodiment will be described based on FIG. 10, FIG. 11, and FIG.
In FIG. 10, a motor 402 constituting a single-phase induction motor includes a main winding 410 and an auxiliary winding 403, and is connected to an AC power supply 407.

  The starter 401 includes a first positive temperature coefficient thermistor 404 connected in series to the auxiliary winding 403 of the motor 402, a semiconductor switch 405 connected in series to the first positive temperature coefficient thermistor 404, and a first positive temperature coefficient thermistor. A circuit is constituted by a second positive temperature coefficient thermistor 406 connected to the auxiliary winding 403 of the motor 402 via the electrode plate I413 in parallel with the 404 and the semiconductor switch 405.

  The first positive temperature coefficient thermistor 404 and the second positive temperature coefficient thermistor 406 self-heat when a current flows, and the electric resistance value rapidly increases.

  The semiconductor switch 405 includes a first terminal T7, a second terminal T8, and a gate terminal G4, and the gate terminal G4 is connected to the second positive temperature coefficient thermistor 406 via the electrode plate B414.

  When a constant current flows through the gate terminal G4, the first terminal T7 and the second terminal T8 are turned on. When no current flows through the gate terminal G4, the first terminal T7 and the second terminal T8 are turned off. However, when no current flows through the second positive temperature coefficient thermistor 406, the resistance value of the second positive temperature coefficient thermistor 406 is small, so that a constant current flows through the gate terminal G4, and between the first terminal T7 and the second terminal T8. Is turned on.

  In addition, when a current flows through the second positive characteristic thermistor 406, the resistance value of the second positive characteristic thermistor 406 increases and the current at the gate terminal G4 decreases, so that there is a gap between the first terminal T7 and the second terminal T8. It becomes OFF.

  11 and 12, one of the opposing electrode surfaces of the second positive temperature coefficient thermistor 406 is connected to the auxiliary winding 403 via the electrode plate A413, and the other electrode surface is connected to the electrode plate B414. To the gate terminal G4 of the semiconductor switch 405.

The outer peripheral surface of the second positive characteristic thermistor 406 other than the electrode surface is surrounded by an air layer 415 defined by the case A411 and the case B412.
The operation and action of the motor starting device configured as described above will be described below.

  When electricity is supplied from the AC power supply 407, a starting current flows through the main winding 410. At the time of start-up, since the temperature of the second positive temperature coefficient thermistor 406 is low and the resistance value is small, a current flows through the gate terminal G4, so that the semiconductor switch 405 is turned on.

  Further, since the temperature of the first positive characteristic thermistor 404 is low and the resistance value is small, a starting current flows through the auxiliary winding 403 and the motor 402 starts operation.

  After the motor 402 is started, the first positive temperature coefficient thermistor 404 self-heats above the Curie temperature within a few seconds, so that the electric resistance value increases rapidly, the current of the auxiliary winding 403 decreases, and the auxiliary winding 403 is substantially reduced. Is cut off.

  Furthermore, since the power supply voltage is also applied to the second positive characteristic thermistor 406, self-heating occurs and the resistance value increases, so that the current to the gate terminal G4 decreases and the semiconductor switch 405 is turned OFF.

  When the semiconductor switch 405 is turned off, the application of the power supply voltage to the first positive temperature coefficient thermistor 404 is cut off, so that the power consumption of the first positive temperature coefficient thermistor 404 does not occur and power can be saved.

  Further, since the air layer 415 in the closed space is formed between the second positive characteristic thermistor 406 and the case A411 and the case B412, the second positive characteristic is excluded except for heat radiation from the opposing electrode surfaces. The heat of the thermistor 406 is not easily transmitted to the case A 411 and the case B 412, and the heat radiation of the second positive characteristic thermistor 406 is reduced.

  In addition, the resistance value of the second positive temperature coefficient thermistor 406 increases as the temperature of self-heating increases, but if the heat radiation to the surroundings is large, the temperature cannot be increased sufficiently, resulting in a small increase in resistance value and consumption. The power increases, and further, the current of the gate terminal G4 does not sufficiently decrease and the semiconductor switch 405 may not be turned off. However, in this embodiment, such an operation error can be avoided.

  Therefore, the power consumption for the heat radiation to the case A411, the case B412 and the like other than the self-heating power of the second positive temperature coefficient thermistor 406 necessary for turning off the semiconductor switch 405 can be suppressed to a very low level. As a result, an extremely energy efficient motor starting device can be obtained.

  Furthermore, since the surface contacting the second positive temperature coefficient thermistor 406 of the case A411 and the case B412 is simply formed into a shape in which the air layer 415 in the closed space is formed, no additional parts are required and the number of assembly steps is also reduced. Since it does not increase, a starter with high productivity and low cost can be obtained.

  As described above, since the motor starter according to the present invention can reduce the power consumption of the positive temperature coefficient thermistor, it can be used for applications such as motors such as refrigerators and air conditioners equipped with the positive temperature coefficient thermistor.

Circuit diagram of motor starter according to Embodiment 1 of the present invention The figure which shows before the assembly of the principal part of the starting device of the motor of the embodiment BB line sectional view after assembly of FIG. Circuit diagram of motor starter according to Embodiment 2 of the present invention The figure which shows before the assembly of the principal part of the starting device of the motor of the embodiment CC sectional view after assembly of FIG. Circuit diagram of motor starter according to Embodiment 3 of the present invention The figure which shows before the assembly of the principal part of the starting device of the motor of the embodiment DD sectional view after assembly of FIG. Circuit diagram of motor starter according to Embodiment 4 of the present invention The figure which shows before the assembly of the principal part of the starting device of the motor of the embodiment EE sectional view after assembly of FIG. Circuit diagram using conventional motor starter The figure which shows the assembly of the principal part of the starting device of the conventional motor AA line sectional view of FIG.

Explanation of symbols

103, 203, 303, 403 Auxiliary winding 104, 204, 304, 404 First positive temperature coefficient thermistor 105, 205, 305, 405 Semiconductor switch 106, 206, 306, 406 Second positive temperature coefficient thermistor 110, 210, 310 , 410 Main winding 115 Vacuum heat insulating material 215 Paint type heat insulating material 311 Case A formed of foamed resin
312 Case B molded from foamed resin
415 Air Layer

Claims (5)

  A motor starter having a main winding and an auxiliary winding, wherein the first positive temperature coefficient thermistor is connected in series to the auxiliary winding, and the semiconductor switch is connected in series to the first positive temperature coefficient thermistor. A first positive temperature coefficient thermistor and a second positive temperature coefficient thermistor connected in parallel with the semiconductor switch to control on and off of the semiconductor switch, and at least one of the outer peripheral surfaces of the second positive temperature coefficient thermistor. Motor starter with a heat insulating layer surrounded by a part.   2. The motor starting device according to claim 1, wherein the heat insulating layer is formed of a vacuum heat insulating material made of a core material and a non-breathable jacket material covering the core material.   2. The motor starting device according to claim 1, wherein the heat insulating layer is formed of a paint type heat insulating material applied to an outer peripheral surface of the second positive temperature coefficient thermistor.   The motor starter according to claim 1, wherein the heat insulating layer is formed of a foamed resin.   The motor starter according to claim 1, wherein the heat insulating layer is formed of an air layer defined by a closed space.

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